International Business Machines Corporation

Fritz J Hohn

Steven D Golladay

William Daniel Meisburger

David J Hutson

Juergen Rasch

Hans C Pfeiffer

George A Sai-Halasz

Mark A McCord

Thomas P Donohue

An X-ray mask membrane 12 is discussed wherein a cantilever and tip portion such as used on an atomic force or scanning tunneling microscope are fabricated directly as part of the mask. The mask is located over a wafer and the vertical (z) motion of the tip with respect to the wafer is achieved with a piezoelectric device which is mounted on a movable support above the cantilever. Piezoelectric device may be a tube having an electrode divided into quadrants so that the end of the tube could be positioned in three dimensions to allow for alignment of the end of the tube to the cantilever tip. X and Y motion of the tip and the mask membrane relative to the wafer is achieved by mounting the wafer on an x-y stage driven by piezoelectric or other transducers. The wafer includes a raised alignment mask on its upper surface. The wafer, mask membrane, and z piezoelectric tube are held rigidly but adjustably with respect to each other by a mechanical fixture. The z piezoelectric tube is lowered until it touches the cantilever; it is then lowered further by the designed gap spacing, deflecting the cantilever downward. The wafer is then raised until it is detected by the tip on the cantilever, either by sensing a tunneling current (STM) or a force (AFM). The wafer is now at the correct z gap setting, and is scanned back and forth in the x and y directions until the location of the alignment mark is determined by the cantilever tip following the contours of the alignment mark, thus setting the proper alignment between the wafer and the mask in the x, y direction.

X-ray mask containing a cantilevered tip for gap control and alignment

An E-beam testing system uses the E-beam to test a sample with conductive elements thereon. The system charges conductive elements on the sample. Above the sample and parallel to its upper surface is a stacked pair of parallel extraction grids. One grid is biased positively to accelerate secondary electrons emitted from the sample. The other grid is biased at a voltage to control the angular distribution of secondary electrons passing through the grid. Rectangular double grid sets, tilted with respect to the beam and the sample, are located above and laterally of the sample and the E-beam. Those grids are charged to attract secondary electrons from the sample. Triangular grids between the rectangular grids and a top grid above and parallel to the sample with an aperture therethrough for the E-beam are biased negatively to repel secondary electrons. Below the rectangular and triangular grids is located a cylindrical attraction grid biased positively, coaxial with the E-beam. A method of testing electrical connections and short circuits of conductors on a body of insulating material without physical contact includes the steps of: a) applying an unfocused flood electron beam with a low current to a broad surface of the body, simultaneously applying a different focused probe electron beam having an energy predetermined to provide a charge of opposite polarity from the flood beam to other areas of the body to be probed, b) generating an electron beam to cause secondary electron emission from the conductors; and c) detecting the presence of connections not at a given potential.

Method for opens/shorts testing of capacitively coupled networks in

An E-beam testing system uses the E-beam to test a sample with conductive elements thereon. The system charges conductive elements on the sample. Above the sample and parallel to its upper surface is a stacked pair of parallel extraction grids. One grid is biased positively to accelerate secondary electrons emitted from the sample. The other grid is biased at a voltage to control the angular distribution of secondary electrons passing through the grid. Rectangular double grid sets, tilted with respect to the beam and the sample, are located above and laterally of the sample and the E-beam. Those grids are charged to attract secondary electrons from the sample. Triangular grids between the rectangular grids and a top grid above and parallel to the sample with an aperture therethrough for the E-beam are biased negatively to repel secondary electrons. Below the rectangular and triangular grids is located a cylindrical attraction grid biased positively, coaxial with the E-beam. A method of testing electrical connections and short circuits of conductors on a body of insulating material without physical contact includes the steps of: (a) applying an unfocused flood electron beam with a low current to a broad surface of the body, simultaneously applying a different focused probe electron beam having an energy predetermined to provide a charge of opposite polarity from the flood beam to other areas of the body to be probed, (b) generating an electron beam to cause secondary electron emission from the conductors; and (c) detecting the presence of connections not at a given potential.

Apparatus and method for opens/shorts testing of capacitively coupled

A system for the detection of features in a semiconductor wafer for registration. An E-beam scans across an insulator covered with a metallic layer. The high energy electrons penetrate and cause the generation of electron/holes pairs. The drift or migration can be sensed as a current, the intensity of which is a function of the applied field strength. The field strength is in turn varied by the topology of the feature or the presence of a junction in the device. Since the E-beam position is known, registration occurs by correlation with the underlying feature as it is mapped out by sensing variations in current. The feature may be an alignment mark or a device under construction on the wafer.

Electron beam lithography alignment using electric field changes to

An electron beam system and method for testing three dimensional networks of conductors embedded in an insulating material specimen without physical contact to detect open and short circuit conditions. Top to top surface wiring is tested by irradiating the specimen with an electron beam at a first beam potential to charge the specimen while negatively biasing a grid placed above the specimen surface, and then irradiating selected portions of the specimen with an electron beam at a second beam potential to read the charge on selected conductors while applying a zero or a positive bias to the grid. In one embodiment the charge beam is a focused scanning beam and the first beam potential is preferably greater than the second beam potential.

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Somers, NY, United States of America

Fritz J Hohn